This happened to me as well. Join me on my journey to find an answer, below
Phrasing the Question
This happens when some systemd
unit fails on the base system. (This has nothing to do with docker, or docker images.)
Presumably, the sshd
server is failing, which may or may not be related to a dropped connection.
You can use these commands to see more information:
$ systemctl --failed
$ systemd status sshd@16493-188.166.209.155:22-222.186.15.79:2573.service
For reference, I’m getting the following error:
Failed to run 'start' task: Transport endpoint is not connected
Finding the Answer
Here is my output from list-units
, which helped me figure this out, finally:
$ systemctl list-units | grep sshd
sshd-keygen.service loaded active exited Generate sshd host keys
sshd@1296-104.236.58.186:22-137.22.169.192:43537.service loaded active running OpenSSH per-connection server daemon (98.22.169.192:43537)
● sshd@532-104.236.58.186:22-277.186.58.136:1283.service loaded failed failed OpenSSH per-connection server daemon (222.186.58.136:1283)
system-sshd.slice loaded active active system-sshd.slice
sshd.socket loaded active listening OpenSSH Server Socket
It looks like sshd.socket
is where the sshd
daemon listens for new connections. The sshd@
lines report one failure and one success (for me). These appear to take the form of
sshd@1234-<server-IP>:<server-port>-<remote-IP>:<remote-port>.service
This explains what happened: I tried logging in from work the other day, and did not have the correct ssh key. So, for me at least, this represents a failed login. While that represents a security crisis averted — and I’m grateful that CoreOS brought this to my attention — I haven’t figured how to clear it out yet.
References:
Postscript
Good luck with your new web service!
{"reason":"Nothing here."}